1.Field
The present disclosure generally relates to: lubrication systems for internal combustion engines, and deals more particularly with controlling the flow of lubricating fluids in such engines.
2. Background
Internal combustion engines have various components such as pistons, shafts and related bearings that require lubrication in order to reduce friction and related wear. Lubrication of these components is typically achieved using a pressurized oil lubrication system having an oil pump that draws oil from an oil sump and pumps it through a series of internal engine passageways and lines to the components requiring lubrication. Adequate lubrication of engine components is more challenging in high-performance applications such as racing engines where rapid changes in engine RPMs and inertial side loads caused by extreme cornering and/or braking may adversely affect oil delivery at the desired pressures.
One example of an engine component requiring lubrication is a bearing supporting an end of a rotating la ye ha ft that is used to transmit motion to camshafts. In some applications, original equipment bearings for this application that are sealed (permanently lubricated) may be retrofitted with a direct oil feed in order to provide the bearing with sufficient lubrication. However, because oil must be diverted to the bearing, this aftermarket solution may result in undesirable reduction of oil pressure at certain locations within the engine, particularly on initial engine start-up. Moreover, the flow of oil provided by the direct oil feed may be insufficient to flush and cleanse the bearing of contaminants.
Inadequate engine lubrication due to oil deprivation and/or inadequate oil pressure may occur for other reasons such as where inertial forces shift oil held within an oil sump or an oil galley. When this local shifting of the oil occurs, it may be temporarily impossible to draw oil from the sump, despite attempts by pressure regulators to compensate for the accompanying drop in oil pressure. Ordinary pressure regulators intended to compensate for these conditions are not entirely adequate and/or are too slow to compensate for transient drops in oil pressure. Under the circumstances just described, oil may temporarily flow backward in oil distribution channels to the oil sump.